determine content-length of html string

Question

I am exporting a HTML table to excel by sending the data as a HTML Table string and setting the content headers:

Dim html as String = "<table><tr><td>example<td></tr></table>"

context.Response.Clear()
context.Response.AddHeader("Content-Disposition", "attachment; filename=" & "exceldata-" & Now.ToString("yyyyMMddHHmmss") & ".xls")
'context.Response.AddHeader("Content-Length", ????)
context.Response.ContentType = "application/octet-stream"
context.Response.Write(response)
context.Response.End()

Is there a simple way of setting the content-length based on the size of the html string? Or should I just leave it blank anyway...would be nice to have the content-length ideally...

I am returning this using a GenericHandler in asp.net

score 5 · Accepted Answer · answered Nov 03 '10 at 02:13

Replace with the encoding of your choice, probably UTF8. Sorry for the C#:

ASCIIEncoding encoding = new ASCIIEncoding();
byte[] bytes = encoding.GetBytes(html);
int length = bytes.Length;

Source: http://msdn.microsoft.com/en-us/library/system.net.httpwebrequest.contentlength.aspx

score 1 · Answer 2 · answered Nov 03 '10 at 01:45

1

This seems too easy, but is it not just equal to html.Length?

answered Nov 03 '10 at 01:45

benr

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6

I guess if each character is a byte, that would make sense? (i hope it is this easy :D) – davidsleeps Nov 03 '10 at 02:08
is this always the case though? – davidsleeps Nov 03 '10 at 02:10
John's answer below is better, go with that. – benr Nov 03 '10 at 02:26

score 1 · Answer 3 · answered Nov 03 '10 at 02:23

I haven't used ASP.NET, but I guess that the Length() method returns the length of the string in chars, not bytes, so it won't work if your server uses UTF-8 or Unicode for serving the pages.

As noted in another answer, just let the server fill it for you. If you think about it, you don't have to add it when you generate HTML pages from ASP since the web server would generate it based in the response from the ASP module.

determine content-length of html string

3 Answers3